Three dimension camera having a film holder

ABSTRACT

A removable film holder is provided for a photographic camera for taking three dimensional photographs in an arrangement wherein a lenticular screen is moved relative to photosensitive material during exposure. A pressure plate is mounted on a housing. Means is provided for moving the pressure plate inwardly and outwardly of the housing in directions substantially normal to the plane of the pressure plate. Means is provided for applying a uniform pressure to the pressure plate in such outward direction with respect to the housing. The pressure plate has a side for engagement with a stop affixed to the housing. Means is provided for urging the pressure plate in a direction substantially parallel with the pressure plate against the stop.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 765,228, filed Feb. 3, 1977now U.S. Pat. No. 4,125,849 issued Nov. 14, 1978.

BACKGROUND OF THE INVENTION

The present invention relates to photographic cameras for taking threedimensional photographs utilizing a lenticular screen.

A number of methods and apparatus have been devised and proposed fortaking and viewing three dimensional photographic pictures. One priorart method and apparatus has two cameras photograph the left and rightimages of an object on film. The exposed film is developed and is thenviewed through a device which allows the user to view the left imagewith the left eye and the right image with the right eye. Disadvantageswith such an arrangement are that two cameras are required for takingthe photograph and further, the three dimensional image cannot be viewedwith the naked eye because some type of viewer, reflective plates orcolored filters are required to avoid reversal of the left and rightimages.

Methods and apparatus have also been proposed for exposing film througha lenticular screen having very small diameter, semicircular andparallel lenticular elements. The exposed film is then viewed through asimilar lenticular screen by the naked eye. Such methods and apparatussequentially expose film through the lenticular screen.

One method and apparatus using a lenticular screen involves a camerawhich is positioned at a number of different angles about the objectbeing photographed, and for each position exposing film through thelenticular screen while moving the lenticular screen.

Another method and apparatus using a lenticular screen eliminates theneed for moving the camera and includes the combination of a lenticularscreen positioned in contact with unexposed film, an objective forfocussing an image of a scene to be photographed on the lenticularscreen, and a shutter which is movable across the path for light raysfrom the objective for sequentially exposing the film. With the lattermethod and apparatus it has been proposed to move at least two of theelements including the objective lens. The lenticular screen, theshutter curtain and the film, during the exposure cycle. However, it hasbeen found to be very difficult to control and obtain sharp threedimensional viewing images using such method and apparatus. As a resultthese methods have generally resulted in low quality three dimensionalphotographs and the method and apparatus have not met with anysubstantial degree of success.

One of the last mentioned method and apparatus involved a camera inwhich there is movement of the film and the shutter curtain relative tothe lenticular screen during the exposure cycle. Relative movementbetween the film and lenticular screen is generally required by someprecise amount. If the precise amount of relative movement is notachieved, the three dimensional quality of the photograph will be pooror the photographic image cannot be seen at all. Where the film is movedit is difficult to control the precise amount of movement of the filmand it is difficult to maintain uniform contact between the film and thelenticular screen. In the camera where the film is moved the shuttercurtain and film are moved in opposite directions and the film is moveda distance substantially equal to the width of two of the lenticularelements. This results in double exposures underneath the lenticularelements, further contributing to poor quality in the three dimensionalphotograph. Additionally, the resulting photograph contains reversedimages under each lenticular element requiring that the images bereversed using a reversing process before the images can be viewed.

The reversing process creates serious problems which make itunsatisfactory and undesirable. Specifically, the exposed film obtainedfrom the exposure cycle of the aforementioned camera is developed into atransparency. A reversing machine positions, in parallel layeredrelation, a lenticular screen adjacent to the transparency which isadjacent to a new unexposed film. The reversing machine moves thelenticular screen, the transparency, and the new unexposed film whileexposing the new unexposed film to an exposure light through thelenticular screen and the transparency. A lenticular screen must beselected which has the same diameter lenticular elements as in thecamera and the distance of movement must be selected to correspond tothe movement of the lenticular screen in the camera. However, the angleof deflection of the objective lens system varies from camera to cameraand as a result a different amount of movement is required in thereversing process for each different objective lens system and hencecamera. As a result it becomes necessary to design a different reversingmachine, or at least select the amount of movement during reversing, foreach different camera. Neither of the aforementioned is practical.

Japanese patent application No. 1971-20693 (Official Gazette No.1972-37637), filed by the present inventor, discloses a camera fortaking three dimensional photographs utilizing a lenticular screen,having small diameter lenticular elements, closely placed adjacent theunexposed film in which the objective lens focusses an image from thescene to be photographed onto the lenticulated side of the lenticularscreen. A shutter screen bearing a shutter aperture is moved across theoptical path between the objective lens and the lenticular screen, whilethe lenticular screen moves a distance equal to one pitch of thelenticular screen. Significantly the shutter and lenticular screen aremoved in the same direction relative to the film and as a result anunreversed three dimensional image is formed on the film. Thus the filmmay be developed into a print and placed behind a lenticular screen fordirect viewing without additional image reversing steps. However, it hasbeen found that such method if practiced as taught will result in areason the exposed film which are not exposed or are double exposed.Therefore when viewed through a lenticular screen after developing, thefilm will appear to have gaps or blank spaces or double exposures,resulting in an unattractive and undesirable photograph.

A further difficulty in obtaining three dimensional photographs comesabout if the unexposed photosensitive material is not uniformlyflattened and spread out against the lenticular screen prior to exposuretime. Any wrinkles, bubbles or irregularities in the photosensitivematerial from a precise uniform plane will cause the resultant threedimensional image to be distorted.

It is desirable if not necessary to provide an actuable means, forexample, a pressure plate for the photosensitive material, which ismoved toward and away from the lenticular screen. The photosensitivematerial is preferably attached to the pressure plate. However, in suchan arrangement the mounting of the pressure plate is such that it willtend to move sideways along with the movement of the screen,contributing to the deficiencies noted above.

BRIEF DESCRIPTION OF THE INVENTION

Briefly an embodiment of the invention is a removable film holder for aphotographic camera in which the lenticular screen is moved relative tothe photosensitive material during exposure. A pressure plate is mountedin a housing. Means is provided for moving the pressure plate inwardlyand outwardly of the housing in directions substantially normal to theplane of the pressure plate. A substantially uniform pressure is appliedto the pressure plate in the outward direction with respect to thehousing. A stop is affixed to the housing. The pressure plate has anedge for engagement with the stop. The pressure plate is urged in adirection parallel with the plane of the pressure plate against thestop.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a cross-section of a camera fortaking three dimensional photographs, embodying the present invention;

FIG. 2 is a pictorial view of a specific camera for taking threedimensional photographs and embodying the present invention;

FIG. 3 is a cross-sectional view of the camera of FIG. 2 taken at therear of the front unit along lines 3--3 of FIG. 2; the rear lenses, theholders for the rear lenses and the rearmost masks have been broken awayto reveal the construction of the shutter curtain;

FIG. 4 is partly a bottom elevation view, partly in cross-section, ofthe front unit of the camera depicted in FIG. 2, taken along the lines4--4 of FIG. 1;

FIG. 5 is a side view of the takeup reels taken along lines 5--5 of FIG.3; the takeup reels are shown partly in cross-section to reveal thespring return mechanism;

FIG. 6 is a plan view of a portion of the housing and the screen start,stop and center position switches, taken along lines 6--6 of FIG. 3;

FIG. 7 is a side elevation view showing the shutter curtain drive reels,the F adjustment mechanism and the screen drive motor and the cams ofFIG. 6 with the portions on the other side thereof removed for clarity;

FIG. 8 is a rear pictorial view of the rear unit of the camera of FIG.2;

FIG. 9 is a section view of the rear unit taken along lines 9--9 of FIG.2;

FIG. 10 is a side elevation view of the rear unit taken along the lines10--10 of FIG. 9 with a portion of the housing broken away to reveal theparts hidden thereby;

FIG. 11 is a plan view of the lenticular screen adjustment mechanismafter the pivoted member has been moved approximately 10°;

FIG. 12 is a view of the delay switch and a portion of the stop switchand the stop for the screen taken from within the circle 12 depicted inFIG. 9;

FIG. 13 is an enlarged cross-sectional view of the film holder in therear unit taken along lines 13--13 of FIG. 8;

FIG. 14 is a plan view of the opposite side of the film holder from thatdepicted in FIG. 8; the side shown contains the pressure plate to whichthe photosensitive material is attached for exposure;

FIG. 15 is a reduced cross-sectional view of the film holder depicted inFIG. 13 taken along lines 15--15 of FIG. 8, depicting a conditionwherein the handle of the film holder has been rotated outwardly 90°with respect to that depicted in FIG. 13 and illustrating a sheet ofunexposed photosensitive material sandwiched between the pressure plateof the film holder and the lenticular screen;

FIG. 16 is an enlarged cross-sectional representation of the pressureplate, a deformed sheet of photosensitive material, a lenticular screen,and glass taken from the circle 16 in FIG. 15; FIG. 16 represents thecondition of the unexposed photosensitive material prior to the initialmovement of the lenticular screen relative to the photosensitivematerial in the direction depicted by the arrow;

FIG. 17 is an enlarged cross-sectional representation of the pressureplate, unexposed sheet of photosensitive material, the lenticularscreen, and the glass taken from the circle in FIG. 15 after thelenticular screen has been moved through its initial movement in thedirection of the arrow to smooth out the photosensitive material;

FIG. 18 is a schematic representation of the electrical control systemfor the shutter motor and the screen motor;

FIG. 19 is a timing diagram illustrating the sequence of operation ofthe electrical control system of FIG. 18;

FIG. 20 is a schematic illustration of the optical system to aid inunderstanding the principles of forming the unreversed images under thelenticular elements; and

FIG. 21 is a schematic representation of the optical system and the wayin which it changes, by a predetermined distance Y, on the surface ofthe photosensitive material, the position of light rays which come froma common point on the scene and which extend along the opposing sides ofthe optical path at the position where the shutter screen sequentiallyopens the path to light rays from the scene.

GENERAL DESCRIPTION

Refer now to FIG. 1 which schematically illustrates an embodiment of thepresent invention. FIG. 1 discloses a photographic camera for takingthree dimensional photographs. Included is a housing 10 which forpurposes of description is substantially in the form of aparallelepiped. A rectangular shaped opening 12 admits light rays to theinterior 14 of the camera housing from, for example, a scene 13.

Also in the optical system 16, means 22 is provided for immovablylocating a sheet of photosensitive material 24 in communication with theinterior of the housing at a location 20 during a time for exposure. Themeans 22 preferably includes a rectangular shaped pressure plate 26 anddouble backed tape (not shown) for attaching the photosensitive material24 to the surface of a rectangular pressure plate.

An optical system 16 in the housing projects light rays, receivedthrough the opening 12, along a path 18. The light rays, receivedthrough the opening 12, are projected along such path to the location 20for the photosensitive material where an image of the scene is focussedon a rectangular shaped lenticular screen 28 which is also a part of theoptical system 16.

The optical path 18 has a first position 32 therealong extending fromside 18a to side 18b of the optical path. To be explained in moredetail, the position 32 is preferably where a shutter curtain ispositioned and is moved across the light rays.

The lenticular screen 28 extends across the path 18 at a second position20 farther along path 18 from the first position 32. Planar side 28a ofthe lenticular screen 28 has elongated lenticular elements extendingperpendicular to the plane of FIG. 1. Each lenticular element, to beexplained in more detail, is of the same width P, is parallel to each ofthe others and faces in the direction from which the light rays arebeing projected. The lenticular screen has an opposite side 28bpositioned for contact with the photosensitive surface of thephotosensitive material 24 when in the location 20.

The optical system 16 is characterized in that it changes, by apredetermined distance, which may be referred to by way of example as Y,on the photosensitive surface of the photosensitive material, theposition of light rays which come from a common point, such as 30, onthe scene and which extend along the first and second sides 18a and 18bof the path. Two such light rays are generally depicted by the brokenlines 18c and 18d by way of example.

Means is provided at 32 for blocking the received light rays andincludes, by way of example, a pair of fixed masks 34 and 36 havingconcentric rectangular shaped apertures, at the center of the opticalpath, and a conventional shutter screen 38 between the masks.

An aperture 40 in the screen 38 is movable across the path 18 at thefirst position 32 from the first side 18a to the second side 18b of thepath for exposing the light rays sequentially to the photosensitivematerial, moving across the lenticular screen 28 in a direction which isnormal to the elongation of the lenticular elements thereon. By way ofexample, the aperture 40 is moved from top to bottom in FIG. 1.

Means 44 is provided for so moving the aperture 40 substantiallythroughout the time for exposure of the photosensitive material 24 whilesimultaneously and synchronously moving the lenticular screen 28. Thelenticular screen 28 is moved substantially throughout the entire timefor exposure of the photosensitive material and in substantially thesame direction as the light rays sequentially expose the photosensitivematerial 24. Significantly the distance by which the lenticular screen28 is moved is substantially equal to the sum of the distances P+Y tothereby expose a continuous unreversed image of the scene on thephotosensitive material. By way of example, the means for moving 44includes a motor 46 for driving the shutter curtain 38 containing theaperture 40, a motor 48 for driving the lenticular screen 28, and anelectrical control circuit 50 which simultaneously and synchronouslymoves the shutter curtain 38 and lenticular screen 28 so that theduration of time during which the aperture 40 passes light to thephotosensitive material 24 and the time for the lenticular screen 28 tomove exactly the distance P+Y are substantially equal. As a result animage is directly produced on the photosensitive material which, whenviewed through a lenticular screen, appears to be three dimensional andsignificantly does not appear to have blank spaces, is not doubleexposed, and appears continuous when moving from one side to the otherduring viewing. It is quite important that the photosensitive material24 be maintained in uniform contact with the lenticular screen 28without wrinkles, bubbles, or other irregularities during the entireexposure time. Means prevent even the slightest movement of thephotosensitive material 24 along with the movement of the lenticularscreen 28. To this end, means in the form of a stop 56 is provided forrestraining movement of the pressure plate 26 in the direction of themovement of the lenticular screen 28 and a spring 57 urges the pressureplate 26 in the direction of and against the stop 56.

DETAILED DESCRIPTION

Consider briefly the principles whereby the images are exposed on thephotosensitive material, unreversed for direct viewing through alenticular screen in three dimensional form. Refer now to FIG. 20.

The object L to be photographed is positioned at X. L₀ is an objective,S₀ is a shutter located behind the objective, and adapted to be openedand closed by movement in a direction transversely to the direction ofthe optical axis, M₀ is a lenticular screen, and F₀ is photosensitivematerial. The objective L₀ is preferably an objective for photographingwhich is cut along parallel planes extending in a direction parallel tothe main optical axis of the objective. Correspondingly and preferably,the shutter S₀ is formed also with an opening S₁ which is elongated in adirection transversely of the cutting parallel planes of the objectiveL₀.

Lenticular screens as depicted at M₀ are well known in the art which aresmooth on one side and have a plurality of elongated, parallel andadjacent lens elements each having the form of a semicylindrical crosssection. Each semicylinder is of uniform width, in cross section, andnarrow, usually in the order to 0.1 to 1 mm. Accordingly, when viewingthe lenticular screen in cross section the boundary lines of adjacentlens elements correspond to opposite ends of each circular arc and whenviewed from the face, define a plurality of stripes extending parallelto each other and transversely to the direction of movement of anoptical aperture or opening S₁ which will be described in more detail.With such an optical system for exposure, the light rays coming from anobjective to be photographed pass through, upon moving of the opening S₁of the shutter S₀, the objective L₀ to the lenticular screen M₀ and thenpass through the latter to the surface of the photosensitive materialF₀. As a result the light rays are subjected to a refraction in both theobjective L₀ and the lenticular screen M₀.

Consider now the way in which the image is formed for the objectdepicted at X and in particular the portion lying between points P andQ. The light rays coming from point P which are incident upon theobjective L₀ are included within a beam θ₁ covering the effectiveaperture of the objective L₀. The light rays coming from the point Qwhich are incident upon the objective L₀ are included within anotherbeam θ₂. Of the light rays included within these beams only that portionthat passes through a particular lenticular element M₂ will be describedfor purposes of explanation.

To facilitate a better understanding of the invention it should be notedthat only three enlarged elements M₁, M₂, M₃ are shown. However, it willbe understood that there are actually a great many more lenticularelements and they are much smaller in scale, all serially arranged andassembled to form a trivision image. The light rays coming from points Pand Q and centrally passing through the objective L₀ form thecorresponding images at points P₂ and Q₂ at the surface of thephotosensitive material F₀. This projection is indicated by solid lines.Of the beam θ₁ coming from the point P, the light rays which areincident not upon the lenticular element M₂ but upon the lenticularelement M₁, adjacent to such lenticular element M₂, are refracted inpassing through the element M₁ and form the image of point P at point P₁on the surface of the photosensitive material F₀. The light rays of thebeam θ₂ coming from the point Q that are incidient not upon thelenticular element M₂ but upon the lenticular element M₃, adjacent tothe lenticular element M₂, are refracted in passing through the elementM₃ and form the image of the point Q at point Q₃ on the photosensitivematerial F₀. It is to be emphasized that only three lenticular elementsM₁, M₂, and M₃ are shown in FIG. 20 on an enlarged scale for convenienceof illustration and that these light rays actually pass through asuccession of other lenticular elements arranged symmetrically about thelenticular element M₂ to form the projected image of that portionincluding the projected images of points P and Q, a projected imagebeing formed by each element.

Directly viewable trivision of a plurality of projected images of thepoints P and Q formed by a plurality of lenticular elements is wellknown. However, the projected image thus formed in each lenticularelement is a reversed image which cannot be directly viewed as thedesired trivisional image. This will be better understood from thefollowing discussion using the image formed by lenticular element M₂ byway of example. Images of the surfaces B, B- and B+ of the trivisionalobject B₀, to be photographed, which lie between the points P and Q, areformed in the reverse order B'+, B', and B'- on the surface of thephotosensitive material F₀. As a result the image of the surface B+ isformed near the image point Q₂ and the image of the surface B- is formednear the image point P₂. Similar reversal is found with respect to theobject A₀ lying between the points L and P whose image is formed in theadjacent lenticular element M₁, and with respect to the object C₀ lyingbetween the points Q and R, whose image is formed in the oppositelyadjacent lenticular element M₃.

Since the image formation on the surface of the photosensitive materialcorresponds to the arrangement of surfaces of the object itself, whichis being photographed, it might be erroneously assumed that theprojected image can be trivisionally viewed. However, when the projectedimage is viewed through a lenticular screen, the image can not be viewedas a trivisional image. This is true because, when viewed through alenticular screen, the left side surface B- of the object B₀ to bephotographed is formed as a left image B'-, and the right side surfaceB+ of the object B₀ is formed as the right image B'+. As a result, theleft image B'- is opposed through the semicylindrical lenticular lensesto the right eye, and the right image B'+ is similarly opposed to theleft eye of the person who is viewing the projected images. As a resultthe right eye views an enlarged image corresponding to the left imageB'-, and the left eye views an enlarged image corresponding to the rightimage B'+, respectively, when viewed through the lenticular screen. Asimilar relationship exists with respect to the objects B₀ and C₀.

To eliminate this phenomena and to obtain a normal trivisional imagewhich is not reversed in the manner discussed above, it is known to movethe lenticular screen M₀ the width of one of the lenticular elements,called one pitch, synchronously with and in the same direction ofmovement with the opening S₁ while holding the surface of thephotosensitive material F₀ fixed relative to the surfaces of thephotosensitive material F₀. As a result, the images of the surfaces A-,A, A+ of the object A₀ between the points L and P are viewed in theorder A'-, A', and A'+ as opposed to the above-mentioned reverse orderA'+, A', and A'- depicted in FIG. 20. Similar comments apply withrespect to the objects B₀ and C₀. As a result the surface of thephotosensitive material F₀ after printing provides a photograph that canbe viewed as a normal trivisional photograph when viewed through alenticular screen M₀ having lenticular elements of the same pitch as thescreen with which the exposure was made.

Thus according to the present invention it is possible to easily obtaina normal trivisional photograph simply by making a single exposure froma single direction.

Having considered the general theory of obtaining the three dimensionalphotograph, the principles according to which the present invention isconstructed should be considered. FIG. 21 is a simplified schematicillustration of a camera for taking three dimensional photographs andembodying the present invention and illustrates the deficiency in thephotographic camera disclosed in the above mentioned Japanese patentapplication where the lenticular screen is moved only by the width ofone lenticular element. FIG. 21 depicts a plan view of a threedimensional object X', a camera including an objective lens L'0, ashutter curtain S'0 with aperture S'1, a pair of masks (MASK) having arectangular shaped opening OP, one mask being positioned on each side ofthe shutter curtain S'0, and a lenticular screen M'0 having elongatedsemicircular spherical elements facing the shutter curtain S'0, theopposite side of the lenticular screen M'0 being positioned in intimatecontact with the exposure surface of unexposed photosensitive materialF0. It will be understood that, for illustrative purposes, thelenticular screen M'0 is shown greatly enlarged from actual dimensionsand only two lenticular elements are shown whereas there are actuallymany more. Each lenticular element has a pitch or width P along theentire length thereof.

Assume that a light beam Ra1 is transmitted from the apex of the objectX'. As indicated, the right hand side has light rays from the dashedline portion 1 of X' whereas the left hand side has light rays from thesolid line portion 2 of X'. Considering the right hand lenticularelement and ignoring the change in angle as the light beam Ra1 entersthe objective L'0, the light beam can be considered as having a portionR'a1 passing from the objective L'0 to the lenticular screen M'0 andstriking the surface of the photosensitive material F0 at P'1. Notehowever that the light beam Ra2 passing from the apex of X' to the lefthand side of the objective L'0 can be considered as having a portionR'a2 leaving the objective lens L'0, striking the surface of thelenticular lens M'0 and striking the surface of the photosensitivematerial F0 at P'2. The distance Y between P'1 and P'2 represents thedisplacement of the light rays, traveling in beam Ra1 and Ra2, due tothe characteristics of the optical system including the objective lensL'0 and the lenticular screen M'0. Similar displacement of the lightrays will be seen with respect to R"a1 and R"a2 under the left handlenticular element.

It should now be apparent that if the lenticular element M'0 is onlymoved by the distance of one pitch, during the time that the apertureS'1 moves from one side of the path for the light rays to the other,there will be a blank unexposed area because of the change in theoptical rays due to the optical system. The present invention eliminatesthat blank space and a true unreversed three dimensional photograph isdirectly obtained, when viewed through a lenticular screen, by movingthe lenticular screen not only the distance P but an additional distancesubstantially equal to the distance Y which is equal to the amount bywhich the optical system changes the position of the light rays on thesurface of the photosensitive material, which light rays come from acommon point on the scene and extend along opposite sides of the pathcreated by the optical system.

With the general principles of the disclosed embodiment of the inventionin mind, consider now a specific camera for taking three dimensionalphotographs and embodying a preferred form of the invention depicted inFIGS. 2-18.

Referring to FIG. 2, a camera for taking three dimensional photographsis disclosed having a housing 100 which is closed except for an opening110. Although not essential to the present invention, the housing 100 isconstructed in modular units in order to allow changeability of parts,changing of film and ease of construction. By way of illustrativeexample the housing 100 has a front unit 102, a bellows 104, a rear unit106 and a film holder 108. The holder 108 is considered herein as partof the housing because it holds the film during exposure but it isactually removable and may be supplied separate from the housing 100.

Referring specifically to FIGS. 2-7, the front unit 102 includes anopening 110 to the housing interior for receiving light rays from ascene. Masks 112 and 114 having concentric rectangular openings arepositioned on each side of a shutter curtain 116. The masks 112 and 114together with their center apertures define the boundaries of the sceneto be photographed and block light rays from passing around theirapertures. In addition the masks 112 and 114 cooperate with the shuttercurtain 116 to completely block any light rays from passing fartheralong the optical path to the photosensitive material until permitted byan aperture 118 in the shutter curtain 116 during exposure time.

The shutter curtain 116 contains aperture 118 which is carried by theshutter curtain. The shutter curtain 116 is movable, from a positionwherein the aperture 118 is completely blocked by the masks 112 and 114,across the rectangular opening provided in masks 112 and 114 to aposition where it is again completely blocked by masks 112 and 114 andwhen blocked prevents light rays from passing on along the light path tothe photosensitive material. Movement of the aperture 118, duringexposure time, is from left to right as depicted in FIG. 2. (from rightto left as depicted from the rear in FIG. 3).

The shutter curtain motive mechanism is well known in the camera art andneed not be explained in detail. However, it should be noted that theshutter curtain 116 includes, for the right side of FIG. 3, a centercurtain part 120 wound on a spring loaded takeup reel 122 (FIGS. 3 and5) and, connected to the center part 120, outer shutter curtain parts124 and 126 wound on outer drive reels 128 and 130 (FIGS. 3 and 7).

The shutter curtain 116 includes, for the left hand side of FIG. 3, acenter shutter part 132 wound on the center drive reel 134 (FIGS. 3 and7) and, connected to the center part 132, outer shutter parts 136 and138 passing around, respectively, lower takeup reels 140 and 142, andwound around and connected to an upper takeup reel 144. The reels 122and 144 are spring loaded as generally depicted in FIG. 5 so as to drawthe shutter curtain taut towards the left hand side of the camera asdepicted in FIG. 1 (the right hand side as depicted in FIG. 3).

Referring specifically to FIGS. 3 and 7, the drive reels 128, 130 and134 are rotatably coupled on a shaft 156 which in turn is rotatablymounted in bearings (not shown) in supports 168 and 170 mounted on thefront face of the housing 100. A D.C. electric motor 158 has itsarmature coupled to the shaft 156 through gear 160, intermediary gear162, and gear 164, the gear 160 being connected to the armature shaftand the gear 164 being connected to shaft 156. Energization of the motor158 causes the gear 160 and hence the shaft 156 to rotate which in turnrotates the drive reels 128, 130 and 134. Thus the motor 158 is part ofthe means for driving the shutter curtain 116 from side to side in themanner to be explained in more detail hereinafter.

The size of the aperture 118 is adjustable from an F setting knob 150.The knob 150 is coupled to a bevel gear 152 which in turn is coupled tobevel gear 154. The bevel gear 154 in turn is rigidly connected to drivereel 134. As a result, rotation of knob 150 rotates the drive reel 134which in turn causes the center portion 132 of the shutter curtain 116to move either to the right or to the left as seen in FIG. 3, dependingon the direction in which the knob 150 is turned. Obviously, movement ofthe center portion 132 to the left will cause the aperture 118 toenlarge and pass more light, whereas movement to the right causes theaperture 118 to become smaller and thus allow less light.

Adjustment of the F setting and hence the size of the aperture 118 byrotation of the drive reel 134 is effected without changing the positionof the drive reels 128 and 130 and hence the position of the outer parts124 and 126 of the shutter curtain. To this end the bevel gear 154 andconnected drive reels 128 and 130 are freely rotatable about the shaft156 whereas the drive reel 134 is rigidly connected for rotation to theshaft 156. Rotation of the knob 150 and hence the drive reel 134 causesa slippage between the reels 130 and 134 through a ring spring 161therebetween when the takeup reels 128 and 126 are held in position bythe unenergized motor 158. When the motor 158 rotates, causing the gears160, 162 and 164 and hence the drive reel 134 to rotate, the spring 161,due to friction between the reels 134 and 130, drives the reels 130 and128 together with the reel 134, thus advancing the aperture from oneside to the other, depending on the direction in which the motor 158 isturning.

Referring specifically to FIG. 4, the optical system includes anobjective lens 170 positioned on the opening 110 side of the shuttercurtain 116 and lenses 172 and 174 positioned on the opposite side ofthe shutter curtain 116. To provide the optimum three dimensionalpictures with the amount of lenticular screen movement used herein it isdesirable that the objective lens 170 be of large diameter, preferably11 c.m. and the horizontal opening through the mask is 8 c.m. Moregenerally the diameters of the lenses 170, 172 and 174 are desirably allgreater than the dimensions of the mask opening and greater than thedistance between the human eyes. The lenses 170, 172 and 174 form acomposite 3 mm standard lens system which provides natural color balanceand minimizes distortion.

Refer now to the rear unit 106 where the lenticular lens and movingmechanism therefor are located. As generally indicated in FIG. 2,preferably a film holder 108 is slid into slots 179 provided on theupper side of the rear unit 106. Referring to FIGS. 9 and 10, alenticular screen 180 is affixed to a clear support and backing such asthe sheet of glass 182. Though not essential to the present invention,the lenticular screen 180 is affixed by cement or other well knownbonding means, only at the top and bottom as depicted in FIG. 9, to theglass 182. Though not essential to the present invention, both thelenticular screen 180 and the glass 182 are substantially square withthe glass 182 slightly larger than the lenticular screen 180. To beexplained in more detail, the unexposed photosensitive material is heldtightly against the outwardly facing surface of the lenticular screen180, depicted in FIG. 9, during the exposure time.

The lenticular screen 180 is lenticulated at the interface between thelenticular screen 180 and the glass 182. The lenticulations on thelenticular screen 180 are preferably semicircular, parallel andelongated from top to bottom as seen in FIG. 9. The distance betweenadjacent junctions of the lenticular elements and the diameter of eachlenticular element are the same and for purposes of explanation arereferred to herein as "P".

The lenticular screen 180 must be precisely moved in a direction betweenthe right and left hand sides of FIG. 9. It is of utmost importance thatthe movement of the lenticular screen 180 be precisely controlled inorder for a complete, accurate and good quality three dimensionalphotograph to be obtained. To this end, guide means in the form of "U"shaped guides 184, 186, 188 and 190 guide the glass 182 in a straightline normal to the elongations of the lenticulations on the lenticularscreen 180. Guides 186 and 188 are partially broken away to reveal theinterior. The guides 188 and 190 are identical, have a flat smoothbearing surface such as depicted at 188a for guide 188, and have legsextending on opposite sides of the glass 182 so as to cause the glass182 to slide, when moved, smoothly and in a straight line in a sidewaysdirection as seen in FIG. 9. The upper guides 184 and 186 are identicalto each other and have leaf spring elements 184a and 186a which engagethe upper edge of glass 182 and urge the glass towards the flat surfacesin the guides 190 and 188. All of the guides 184-190 are generallyU-shaped to extend on opposite sides of the glass 182 to prevent theglass from moving in a direction perpendiclar to the plane of FIG. 9.

A link 196 is connected between a pivotally mounted member 194 and theglass 182. A bolt 198 is affixed to the link 196 and extends into anelongated slot 199 in the pivoted member 194. With this arrangement thepivoted member 194 is free to rotate about the bolt 198 and to slidealong its elongation relative to the bolt 198 for the reasons to bedescribed in more detail hereinafter. A motor 200 together with a piniongear 202 and a rack 204 form a motive means for pivotally moving thepivoted member 194 about its pivot and as a result for moving the glass182 and the lenticular screen 180. Referring to FIGS. 8 and 9, means 205is provided for relatively adjusting the distance between the pivotprovided by bolt 198 and the connection, provided by link 196. Thisconstruction allows the amount of movement of the lenticular screen 180to be precisely controlled during exposure time as will be described inmore detail hereinafter.

Specifically, pitch control and lock knobs 206 and 208 are connected toshafts 210 and 212. The shaft 212 has a ring shaped collar 216 affixedin an axial direction thereto and an end 214 threaded into the housing100 at rear unit 106 of the housing. In between the housing and the lockcollar 216 and included in the adjusting means 205 is an elongatedmember 218 which slides vertically as seen in FIG. 9 and left and rightas seen in FIG. 10. The elongated member 218 carries the pivot bolt 192,the pivoted member 194, motor 200, rack 204 and pinion 202. In additionthe elongated member 218 has an elongated slot 220 through which theshaft 212 freely extends. Rotation of the knob in one direction causesthe collar 216 to clamp the elongated member 218 against the housing100, whereas rotation in the other direction removes the clamp, allowingthe member 218 to be moved and thereby change the position of the pivotat 198 (for the lenticular screen) relative to the pivot at 192 (for thepivoted member 194).

The pitch control knob 206 and the shaft 210 cooperate with a rack 221to allow controlled and accurate adjustment in the position of member218. To this end the shaft 210 has threads extending lengthwise which inturn mate with the teeth in the rack 221. The lower end of the shaft 210as seen in FIG. 10 is rotatably mounted in the rear unit 106 of thehousing by means not shown. The motor 200 is affixed by means of abracket 223 to the elongated member 218 and hence is carried withmovement of the member 218.

The pinion 202 is connected to the armature of the motor 200 and mateswith rack 224 pivotally mounted on the adjacent end of the pivotedmember 194. The pivot is provided by a bolt 228 extending through thepivoted member 194 and significantly allows the rack 224 to maintain itsteeth oriented parallel with the teeth in the pinion 202 as the motormoves the rack 224 from side to side. FIG. 9 depicts the pivoted member194 in substantial alignment with the pinion 202 whereas FIG. 11 showsthe pivoted member 194 pivoted to the right. In both cases the teeth inthe rack 224 and in the pinion 202 remain aligned. This construction isimportant in causing smooth continuous and accurate movement of thelenticular screen by the motor 200.

Referring to FIGS. 8, 13, 14 and 15 the film holder 108 is slid intoU-shaped slots at 179 provided on each side of the rear unit 106 whichform means for permanently locating photosensitive material duringexposure time. Referring to FIGS. 13 and 14, the film holder 108 has arear surface 252 having a shaft 254 extending normal therethrough whichin turn has a handle 256 rotatably mounted on a pin 258 extendingthrough the shaft 254 at right angles thereto. The shaft 254 has a ringat the interior of the film holder 108 which fits in a cavity forming apart of the rear surface of a pressure plate 262. With this constructionit will be seen that movement of the shaft 254 to the left as seen inFIG. 13 draws pressure plate 262 inward with respect to the holder,whereas movement of the shaft 254 to the right causes the pressure plate262 to move outward. When the handle 256 is in the down positiondepicted in FIG. 13, a pair of pins (only one being shown) 264 extendingin opposing directions from the handle 256 engage a landing 268 mountedon the rear surface 252, forcing the shaft 254 to its full position tothe left. Rotation of the handle 256 to the outward position shown inphantom line in FIG. 13 moves the shaft 254 away from the landing 268allowing the shaft 254 and hence the pressure plate 262 to move outwardto the right.

A center coil compression spring 270 between the pressure plate 262 andthe rear surface 252 urges them apart. Four coil compression springs272, 274, 276 and 278 together with spring 270 apply a uniform pressureover the entire pressure plate 262, tending to move it to the right asdepicted in FIG. 13.

As depicted in FIG. 14, the springs 272, 274, 276 and 278 aresymmetrically positioned about the center spring 270 so that uniformpressure is applied by the pressure plate 262 when the handle 256 isrotated outward.

Referring to FIG. 8, lock bolts 252 and 254 are threaded through thehousing 100 of the rear unit 106 and when tightened inward engage andhold the film holder 108 fixed in the rear unit 106. The nuts 252 and254 are loosened to allow removal of the film holder from the slots 179.

Refer now to FIG. 15. FIG. 15 shows a cross-sectional view of the filmholder 108 positioned adjacent the lenticular screen 180. Positionedbetween the lenticular screen 180, as may be more clearly seen in theenlarged cross-sectional view of FIGS. 16 and 17, is a sheet ofunexposed photosensitive material 280. The handle 256 of the film holder108 is in the outward position allowing the springs to uniformly loadthe pressure plate 262 against the sheet of photosensitive material 280thereby sandwiching it tightly between the pressure plate 262 and thelenticular screen 180.

The photosensitive material may be attached to the surface of thepressure plate 262 seen in FIG. 14 in any one of a number of ways wellknown in the camera art. The lines on the pressure plate 262 depicted inFIG. 14 may be used for aligning the film so that it is symmetricallypositioned with respect to the center of the pressure plate 262.Preferably the photosensitive material 280 is attached to the pressureplate 262 by double backed adhesive positioned along the upper side ofthe photosensitive material 280, although other means for attachment maybe used. To be explained in more detail, the lenticular screen 180 ismoved with the glass 182 to the left as depicted in FIG. 16. Frictionbetween the lenticular screen 180 and the photosensitive material 280may tend to cause the pressure plate 262 to move with the lenticularscreen to the left, preventing a complete movement of the lenticularscreen 180 relative to the photosensitive material 280 during thelimited exposure time. Accordingly stops 290 and 292 (FIGS. 14 and 15)are provided along the side of the housing for the film holder 108 andengage the pressure plate 262. Such engagement is ensured by a sideloading spring 282 (FIG. 15). As a result the pressure plate 262 isrestrained against side movement when the lenticular screen 180 is movedto the right as seen from the front (to the left in FIGS. 9, 14 and 15)relative to the photosensitive material during exposure time.

Before considering the operation of the camera with respect to theschematic diagram of FIG. 18, consider the various electrical sensingswitches, stops, and cams. Referring to FIG. 6, cam 304, driven by theshutter curtain motor 158 which in turn actuates left stop switch SW3,right stop switch SW2 and center stop switch SW1 for the shuttercurtain, the directions being given from the front of the camera as seenin FIG. 2 and the positions being in relation to the positions of theaperture of the shutter screen. Referring to FIG. 9, stops 320 and 322are mounted on the glass 182 for actuating lenticular screen switches.Specifically, stop 322 actuates left stop switch SW5, delay switch SW4and stop 320 actuate right stop switch SW6, all directions being givenwith respect to the front of the camera in FIG. 2 and all being withrespect to the position of the lenticular screen 180 (or glass 182).

Referring to FIG. 18, the motors 158 and 200 are conventional D.C.motors each having armature and field windings. Conventional four speedshutter speed controls 300 and 302 control the electrical signal to thewindings of motors 200 and 158, respectively. The controls 300a and 302aof the shutter speed controls 300 and 302 are connected together tospeed control knob 310 on the rear unit 106 so that their settings areadjusted to cause the motors 200 and 158 to rotate at the proper speeddetermined by the setting of knob 310. The switches SW1-SW6 are allconventional normally closed open micro switches having an actuator armwhich when depressed by the corresponding stop electrically opens a setof contacts breaking electrical continuity therebetween. The contactsare depicted schematically in FIG. 18 and the corresponding position inthe electrical circuit between which they are connected is depicted by a. For example, switch SW1 has sides "a" and "b" of its contactsconnected between lines "a'" and "b'".

The cycles (FIG. 19) of operation of the camera are controlled by afocus switch SW7, a remote switch SW8, and a shutter set switch 310 onthe rear unit 106 of the camera (FIG. 8). The remote switch SW8 withcord and connector plug into a remote connector receptacle shown in therear unit 106.

Consider now the operation of the photographic camera according to thepresent invention, making reference to the schematic diagram of FIG. 18and the timing diagram of FIG. 19. Assume that the shutter screen ispositioned with the aperture 118 positioned on the left hand side of thefront of the camera (FIG. 2) behind the mask 112 so that no lighttravels along the optical path to photosensitive material positioned onthe pressure plate 262 of holder 108. Also assume that an exposure cycleis taking place as depicted at "a" in FIG. 19 where the focus switch SW7is in the off position causing its contacts to be closed. With theshutter curtain and lenticular screen positioned fully to their leftpositions, left stop switches SW3 and SW5 and delay switch SW4 areactuated causing their contacts to be opened and right stop switches SW2and SW6 are now deactuated and their contacts are closed. Assume thatremote switch SW8 is actuated causing a 9 volt source of potential (notshown) to be applied along the conductors going to shutter speed controlcircuit 300 and screen speed control circuit 302. The screen speedcontrol motor 302 in turn applies power through the closed contacts SW6through the contacts of the shutter setting switch 310 to the armatureof the motor 158 causing from left to right across motor 158 a + to -voltage and applying a control signal to the field of the motor 158.This causes the screen pitch control motor 158 to start driving thelenticular screen 180 towards the right hand side of the camera.However, since the delay switch SW4 is now actuated and its contacts areopen, no power is applied to the shutter speed control 300. With thescreen 180 moving, shortly the left end stop switch SW5 is deactuatedbut the motor 158 continues driving the screen towards the right.Subsequently the delay switch SW4 is deactuated, allowing its contactsto be closed, thereby closing the circuit between the 9 volt D.C. sourceof power and the shutter speed control 300 which in turn applies powerto shutter motor 200, causing it to commence driving the shutter andaperture 118 towards the right.

It should be noted at this point that the lenticular screen 180 startedmoving prior to the commencement of movement of the shutter. The timeperiod during which the screen moves prior to the commencement ofmovement of the shutter is depicted by "time delay" in "a" of FIG. 19and is the time between the time the screen motor commences itsoperation and the time that the delay switch SW4 is deactuated, causingthe shutter motor to start driving the shutter. Referring to FIG. 16 itis possible that the photosensitive material 280 may have wrinkles orbubbles which were not smoothed out merely by the pressure of thepressure plate 262. This is depicted by the exaggerated illustraion ofFIG. 16. By causing the above described preliminary movement of thescreen and holding the pressure plate 262 fixed against the stops 290and 292, the photosensitive material 280 is caused to smooth out becauseof the preliminary wiping action of the lenticular screen 180. The delaytime before switch SW4 is deactuated allows sufficient movement of thescreen relative to the pressure plate so that the photosensitivematerial is smoothed out into uniform contact with the screen prior tothe exposure time.

Continuing with the operation, both the shutter motor 200 and the screenmotor 158 continue to rotate and hence move the shutter curtain and thelenticular screen. As the cam 304 rotates it will briefly engage theactuator arm on the center stop switch SW1, opening and closing itscontacts. However, the contacts of the center stop switch SW1 are nowshorted through the closed contacts of the focus switch SW7 and hencepower to the shutter motor 200 is not broken. The shutter continuesmoving towards the right as depicted in FIG. 2 until the cam 304 engagesthe actuator arm of the right stop switch SW2 at which time the circuitfrom the shutter speed control 300 to the armature of the shutter motor200 is broken, stopping movement of the shutter motor and hence theshutter. However, the screen motor 158 is still being energized andhence continues to move the lenticular screen 180 towards the rightuntil the right stop switch SW6 is actuated, opening its contacts. Whenthe right stop switch SW6 is actuated and its contacts open, power isbroken from the screen speed control circuit 302 to the screen motor158, stopping its operation and hence movement of the screen.

For purposes of explanation it is assumed that the exposure cycle ofFIG. 19a produces an exposure time of one second. Under thesecircumstances the shutter motor is energized for one second which inturn causes the aperture 118 in the shutter to allow light rays to passto the photosensitive material for one second.

Assume now that it is desired to take another photograph and thereforethe camera is to be refocussed and reset ready for another exposurecycle. Initially the sequence of operation depicted in "b" of FIG. 19takes place. Specifically the focus switch SW7 is placed in an ONposition causing its contacts to be open as depicted in FIG. 18.Additionally the switch 310 is set to a setting position and hence allof its contacts are in the lower position opposite to that depicted inFIG. 18. Also at this point in time both the shutter and the lenticularscreen are at the right hand side of the camera as depicted in FIG. 2,causing the switches SW2, SW6 to be actuated and hence their contactsare open. Additionally the left stop switches SW3, SW5 and the delayswitch SW4 are deactuated, causing their contacts to be closed. Assumenow that the remote switch SW8 is actuated, causing power to be appliedfrom the 9 volt source of power to the shutter speed control 300 and thescreen speed control 302. The power applied to the armature of themotors 200 and 158 has now been reversed by virtue of the change inposition of the switch 310 to the setting position. Hence the motorsstart driving the screen and shutter towards the left hand side of thecamera as seen in FIG. 2. This operation continues until the shuttermotor 200 rotates the cam 304 into engagement with the actuator arm ofthe center stop switch SW1 at which time its contacts are open. Sincethe focus switch SW7 is now in an ON position and is contacts are open,the broken contacts of switch SW1 break the power to the shutter motor200, leaving the aperture 118 at the center of the opening 110 as seenin FIG. 2. However, power continues to be applied to the screen motor158, driving it towards the left. Subsequently the delay switch SW4 isactuated but since the shutter motor 200 has already been stopped, ithas not effect. The screen continues to move until the left stop switchSW5 is actuated, causing the contacts of SW5 to be open and therebybreak power to the screen motor 158, stopping the movement of the screenmotor and the screen.

With this position of the screen and the shutter it is now possible toloosen bolts 252 and 254, remove the film holder from the rear unit 106of the camera and look through the camera and adjust the distancethrough the center bellows between the front unit 102 and the rear unit106 in order to focus the camera for the next scene to be photographed.After focussing, the film holder 108, loaded with new unexposedphotosensitive material and covered with shield 279, is returned to theslots 179 in the rear unit 106. After the film holder is inserted, thelocking bolts 252 and 254 are tightened against the film holder and theshield 279 is removed, placing the photosensitive material on the filmholder in the path for light rays through the camera. The handle 256 isthen turned 90° from that depicted in FIG. 8 causing the pressure plateto move the photosensitive material tightly against the lenticularscreen. Next, the off-focus cycle depicted at "c" in FIG. 9 takes place.During the off-focus cycle the shutter and lenticular screen are to becompletely positioned to the right, preparatory for the last or settingcycle "d" where both are reset completely to the left, ready for a newexposure cycle.

Referring to the off-focus cycle at "c" of FIG. 19, the focus switch SW7is positioned to the OFF position with its contacts closed (i.e.,opposite to that depicted in FIG. 18). Additionally the switch 310 isset to the shutter position. Subsequently the remote switch SW8 isactuated, applying power to the screen speed control 302 which in turnapplies power across the screen motor 158 (+ to - across the armature asdepicted in FIG. 18), causing the motor 158 to start driving the screento the right. However, the delay switch SW4 is initially actuated, henceno power is applied to the shutter speed control 300 and the shuttermotor 200 remains deenergized. Subsequently the left stop switch SW5 isdeactuated and later the delay switch SW4 is deactuated, closing theircontacts and thereby connecting 9 volts D.C. to the shutter speedcontrol 300, starting its operation. Similar to the screen motor 158,power is applied across the armature of the motor 200, + to - asdepicted in FIG. 18, causing the shutter motor 200 to commence movingits shutter aperture from the center of the opening 110 to the righthand side. This operation continues until the right stop switch SW2 isactuated, opening its contacts and thereby breaking the power to thearmature of the motor 200, stopping its operation. The screen motor 158continues rotating until the right stop switch SW6 is actuated, causingits contacts to open and thereby break power to the screen motor 158.

At this point the setting cycle depicted at "d" in FIG. 19 is commenced.Initially both the screen and the shutter are positioned at the rightand hence the right stop switches SW2 and SW6 are operated, causingtheir contacts to be open, whereas the left stop switches SW3 and SW5and the delay switch SW4 are deactuated with their contacts closed. Theswitch 310 is set to the setting position where its wiper is at thelower position depicted in FIG. 18 and the focus switch SW7 is switchedto the OFF position with its contacts closed (i.e., opposite to thatdepicted in FIG. 18). Subsequently the remote switch SW8 is actuated,connecting the 9 volt D.C. power to both the shutter speed control 300and the screen speed control 302. This causes both of the motors tooperate and drive the shutter to the left hand side with the aperturehidden behind the masks and drive the screen 180 to the left. Similar tothat described above, the shutter motor 200 is shut off when the shutteraperture reaches its left hand extremity and the left stop switch SW3 isactuated, whereas the screen motor 158 is shut off when the screenreaches the left hand extremity, actuating the left stop switch SW5.Thus the camera is now ready for another exposure cycle.

As depicted in FIG. 9, stops 320 and 322 are provided for engaging,respectively, the switches SW6 and SW5, SW4. The stop 322 has a frontedge 324 which engages the actuator arm of the left stop switch SW5.However, the stop 322 has a spring loaded plunger 326 for actuating theplunger or actuator arm 328 of the switch SW4. Because of the springloaded plunger 326, the plunger 328 and hence switch SW4 is maintainedin an actuated position for the initial time delay period required forthe screen to smooth out the photosensitive material after operation ofthe screen motor 158 is commenced.

Although an exemplary embodiment of the invention has been disclosed forpurposes of illustration, it will be understood that various changes,modifications and substitutions may be incorporated into such embodimentwithout departing from the spirit of the invention as defined by theclaims appearing hereinafter.

What is claimed is:
 1. A removable film holder for a photographic camerafor taking three dimensional photographs wherein a lenticular screen ismoved relative to photosensitive material during exposure, thecombination comprising:a housing; a pressure plate mounted on saidhousing; means for moving said pressure plate inwardly and outwardly ofsaid housing in directions substantially normal to the plane of suchpressure plate; means for applying a uniform pressure to said pressureplate in such outward direction with respect to said housing; a stopaffixed to said housing; said pressure plate having a side forengagement with said stop; and means for urging said pressure plate in adirection subtantially parallel with said pressure plate against saidstop.
 2. A removable film holder according to claim 1 comprisingactuable means mounted on said housing for locking said pressure platein the inward direction of said housing against the urging of saiduniform pressure applying means and for releasing said pressure platefor movement in such outward direction.